Media files generally contain the media content data as well as other information that may describe the media file such as headers or information that describes the content contained therein such as metadata. Metadata pertaining to a still image, for example, can be embedded into a header of the image file which in one exemplary embodiment is an image e using the JPEG format having and EXIF (Exchangeable Image File Format) header. The EXIF standard supports metadata related to attributes of the image's content. These attributes are stored in tags incorporated into the EXIF. Semantic image metadata, for example, is carried in either the “ImageDescription” or “UserComment” tags of the file. In order to enrich the metadata vocabulary and therefore the features available to applications, it is only possible to use a formatted-text syntax in “UserComment” tag. The ImageDescription tag is not appropriate, since it cannot carry binary payloads. While this solution is simple, it is constrained by the amount of metadata tags that can be efficiently used. Richer metadata vocabularies exist and can be expressed in textual format. Such is the case of MPEG-7, for example, which is expressed in XML. However, a textual MPEG-7 XML description is typically too verbose to be efficiently carried in the User-Comment tag of an EXIF header. Therefore, a better solution is necessary to embed rich metadata in a metadata header capable of binary data payloads.
Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions and/or relative positioning of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of various embodiments of the present invention. Also, common but well-understood elements that are useful or necessary in a commercially feasible embodiment are often not depicted in order to facilitate a less obstructed view of these various embodiments of the present invention. It will further be appreciated that certain actions and/or steps may be described or depicted in a particular order of occurrence while those skilled in the art will understand that such specificity with respect to sequence is not actually required. It will also be understood that the terms and expressions used herein have the ordinary meaning as is accorded to such terms and expressions with respect to their corresponding respective areas of inquiry and study except where specific meanings have otherwise been set forth herein.